Modern web applications load and execute a lot more JavaScript code than they did just a few years ago. While JIT (just-in-time) compilers have been very successful in making JavaScript performant, we needed a better solution to deal with these new workloads. To address this, we’ve added a new, generated JavaScript bytecode interpreter to the JavaScript engine in Firefox 70.

JAVASCRIPT UPGRADE

How to optimise React with Hooks for performance? How to building a REST API with Koa? How OOP works in JavaScript? What is ReasonML and why use it? How to build a Chrome extension with React And Parcel? Those and many other defferent topics are covered in these weekly videos. As always, WJS readers can use this link to subscribe with 22% off.

REACT

Plumbing in programming is something you have to do to make things work. It’s sometimes repetitive or looks like a boilerplate you would usually remove. It’s also crucial because it connects different layers of the application. In this post, I’ll show you a typical example of plumbing inside a React application and a way to fix it.

TESTING

An underrated feature of Jest is customizing the assertion errors that the console displays when tests fail. Imagine the following test code, which needs to programmatically loop an object to ensure keys exist as expected...

REASONML

TUTORIALS

When I first started working as a professional web developer back in 2008 I knew some HTML, CSS and PHP. At the same time I was also learning this thing called JavaScript because it allowed me to show and hide elements and do cool things like dropdown menus.